“Skin disinfectants” are routinely used in professional and non-professional contexts to rapidly kill microbes. A physician has a need to disinfect his or her skin both before and after examining a patient. Prior to the performance of an invasive medical procedure, the skin of the subject must be properly cleaned to avoid post-procedure infections. In non-professional contexts, a commuter, riding public transportation, may wish to disinfect her hands before handling food; a child, playing in a park, may need to clean his hands but not have the convenience of soap and water nearby. Each of these situations require, optimally, a skin disinfectant that is effective, easy to use, and non-irritating so as to permit repeated use.
A number of skin disinfectants have been developed that use alcohol as the primary antimicrobial agent. There are two general problems associated with alcohol-based disinfectants. First, the effective concentration of alcohol, generally regarded to be greater than about 60 percent weight (hereafter, all percentages should be considered weight/volume percentages, unless specified otherwise) of ethanol, or its equivalent, is irritating to the skin, causing dryness and consequent peeling and cracking. Because chapped skin tends to be more susceptible to microbial contamination, repeated use of alcohol disinfectants can exacerbate the very problem they are intended to solve. Second, whereas alcohol can be an effective disinfectant, once it evaporates its antimicrobial activity is lost.
Alcohol-based skin disinfectants which are known in the art, some of which address the two problems mentioned above, include the following.
U.S. Pat. No. 6,107,261 by Taylor et al., issued Aug. 22, 2000, and its continuations-in-part, U.S. Pat. No. 6,204,230 by Taylor et al., issued Mar. 20, 2001 and U.S. Pat. No. 6,136,771 by Taylor et al., issued Oct. 24, 2000, disclose antibacterial compositions which contain an antibacterial agent at a percent saturation of at least 50 percent. The compositions further comprise, as solubility promoters, a surfactant and a hydric solvent, which may be an alcohol.
U.S. Pat. No. 5,776,430 by Osborne et al., issued Jul. 7, 1998, discloses a topical antimicrobial cleaner containing about 0.65-0.85 percent chlorhexidine and about 50-60 percent denatured alcohol, which is scrubbed onto and then rinsed off the skin.
European Patent Application 0604 848 discloses a gel comprising an antimicrobial agent, 40-90 percent by weight of an alcohol, and a polymer and thickening agent.
U.S. Pat. No. 4,956,170 by Lee, issued Sep. 11, 1990 relates to a high alcohol content antimicrobial gel composition which comprises various emollients and a humectant to protect the skin from the drying effects of the alcohol. In alcohol formulations, higher levels of alcohol are needed to provide instant kill against sensitive as well as resistant strains of bacteria.
Certain formulations virtually omit alcohol as a primary antimicrobial agent, such as, for example, the skin sanitizing compositions disclosed in U.S. Pat. No. 6,187,327 by Stack, issued Feb. 13, 2001, which comprises triclosan (2,4,4′-trichloro-2′-hydroxydiphenyl ether; concentration 0.1-0.35 weight percent) in a topical lotion comprised of a surfactant phase and a wax phase, which purportedly provides antimicrobial protection for 3-4 hours after application. The composition prepared according to the claims of U.S. Pat. No. 6,187,327 further comprises chlorhexidine digluconate.
U.S. Pat. No. 5,965,610 by Modak et al., issued Oct. 12, 1999, teaches skin cleaning compositions comprising antimicrobial agents and zinc salts, where zinc salts have a soothing effect on the skin. The claimed subject matter includes formulations comprising a gel formed between zinc gluconate, chlorhexidine gluconate and a solvent, to which various thickening agents, emulsifying agents and/or emollients may be added.
U.S. Pat. No. 5,985,918 by Modak et al., issued Nov. 16, 1999, relates to “Zinc-Based Anti-Irritant Creams”.
U.S. Pat. No. 5,705,532 by Modak et al., issued Jan. 6, 1998, relates to “Triple Antimicrobial Compositions” comprising less than or equal to two percent of a chlorhexidine compound, less than or equal to 0.1 percent of a quaternary ammonium compound, and less than or equal to two percent parachlorometaxylenol.
Octoxyglycerin, sold under the trade name Sensiva® SC50 (Schulke & Mayr), is a glycerol alkyl ether known to be gentle to the skin. Octoxyglycerine exhibits antimicrobial activity against a variety of Gram-positive bacteria associated with perspiration odor, such as Micrococcus luteus, Corynebacterium aquaticum, Corynebacterium flavescens, Corynebacterium callunae, and Corynebacterium nephredi, and is used in various skin deodorant preparations at concentrations between about 0.2 and 3 percent (Sensiva® product literature, Schulke & Mayr).
For example, U.S. Pat. No. 5,885,562 by Lowry et al., issued Mar. 23, 1999, relates to deodorant compositions comprising an antimicrobial agent, namely polyhexamethylene biguanide (at a concentration of between 0.01 and 0.5 percent), together with a polarity modifier such as Sensiva®SC50, at levels of typically 1-15 percent. Compositions disclosed in U.S. Pat. No. 5,885,562 may further comprise a short chain monohydric alcohol such as ethanol at a level of between 20 and 80 percent. Formulations useful as deodorants, however, would differ from those used as skin sanitizers in that skin sanitizers would optimally exhibit rapid broad spectrum activity against bacteria, fungi, and viruses, not merely gram positive odor causing bacteria.
U.S. Pat. No. 5,516,510 by Beilfuss et al., issued May 14, 1996, discloses deodorant compositions which comprise glycerin monoalkyl ethers such as octoxyglycerin (referred to therein as 2-ethyl hexyl glycerin ether, and as being the most preferred among these compounds). The deodorant compositions of U.S. Pat. No. 5,516,510 may be formulated in aqueous and/or alcoholic solutions and may further comprise additional antimicrobial compounds, including triclosan, chlorhexidine salts, alexidine salts, and phenoxyethanol, among others. Specific concentration ranges for triclosan and the biguanides are not provided.